Hybrid Lipid/Clay Carrier Systems Containing Annatto Oil for Topical Formulations De Melo Barbosa, Raquel García Villén, Fátima Sánchez Espejo, Rita María Cerezo González, María Pilar Viseras Iborra, César Antonio Hybrid system Topical formulations Colloidal suspension Bixa orellana L. Financial support for this research was provided by the Coordination of Improvement of Higher-Level Personnel-Brazil (CAPES)-02817/09. RMB and FNR acknowledge fellowships from National Council for Scientific and Technological Development CNPq (Brazil). This research also was financially supported by Junta de Andalucia, under the project reference PT18 RT 3786. Nanocomposites formed by clay and lipid carriers (NLCs) show a high potential for providing controlled release and specific delivery of bioactive molecules and have recently gained attention in the pharmaceutical sector due to their ability to transport hydrophilic and hydrophobic drugs. Recent studies have recognized the biological activity of the oil of Bixa orellana L. (AO) with regards to its healing, antioxidant, antibacterial, and anti-leishmanial properties. Therefore, the purpose of this study is the preparation and characterization of hybrid systems based on lipid nanocarriers and laponite for the delivery of AO. NLCs were prepared by the fusion-emulsification method, using cetyl palmitate (CP) or myristyl myristate (MM), AO, and Poloxamer 188. The morphology, hydrodynamic diameters, zeta potential (ZP), polydispersity index (PDI), thermal analysis, X-ray diffraction analysis (XRD), viscosity behavior, and cytotoxicity testing of the hybrid systems were performed. The thermal study and X-ray diffraction analyses (XRD) revealed polymorphic structural changes compatible with the amorphization of the material. Rheological assays highlighted a typical pseudoplastic behavior in all systems (MM and CP with LAP). The hybrid systems’ morphology, size diameters, and PDIs were similar, preset spherical and monodisperse structures ( 200 nm; <0.3), without significant change up to sixty days. The ZP values differed from each other, becoming higher with increasing AO concentration. XEDS spectra and elemental X-ray maps show peaks of lipids (organic components, C and O) and inorganic components O, Mg, and Si. All samples showed cell viability above 60%. The results indicated a stable, biocompatible hybrid system that can be an alternative for topical application. 2022-06-15T08:03:35Z 2022-06-15T08:03:35Z 2022-05-17 info:eu-repo/semantics/article Barbosa, R.d.M... [et al.]. Hybrid Lipid/Clay Carrier Systems Containing Annatto Oil for Topical Formulations. Pharmaceutics 2022, 14, 1067. [https://doi.org/10.3390/pharmaceutics14051067] http://hdl.handle.net/10481/75497 10.3390/pharmaceutics14051067 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España MDPI